> To be fair, one of the most vocal advocates of higher code quality is Carmack, who has put out a few games.
I'm working on a port of Doom right now, and have worked with the Quake 2 source code before. I also took a quick look at the Wolfenstein source code yesterday.
It's very clear that Carmack and his colleagues have developed their craft over time. Wolfenstein doesn't seem to have much structure to it at all. Doom is still a mess of global variables and ugly code. But you're starting to see some nice abstractions, like the WAD loading (which made it modder friendly) and the sound module system.
It's been a while since I worked with the Quake 2 code, but I remember it being quite elegant. From what I've heard the Doom 3 source code is excellent.
I think the point is, for your first projects, for small indie-style games, you really shouldn't worry too much. In my experience, it's really hard to learn to use good abstractions effectively unless you've tried to do things the hacky way first, and actually have a solid feeling for what the abstractions try to solve. I still notice this, that I really have trouble getting some projects off the ground if I try to do it the elegant way from the start. Sometimes you spend too much time with an abstraction that turns out to be a bad fit. If I just hack it together, and then refactor it later, it's much easier to get things started.
It's also important to remember that the more people you're collaborating with, the more important it is to have a clean structure.